- Apr 05, 2017 -

C-rates

Charge and discharge rates are often denoted as C or C-rate, which is a measure of the rate at which a battery is charged or discharged relative to the capacity of the battery. Any battery has an energy capacity which is given in amp-hours or milliamp-hours (i.e., capable of delivering so much current for so many hours). The C-rate is amp or milliamp figure when charging a battery.

For example, for a battery with a capacity of 500mAh, the current corresponding to a C-rate of 10 is a charge rate of 5000mA (or 5A), while the current corresponding to a C-rate of 1/2 is 250mA.[3]

Very rapid charging rates, 1 hour or less, generally require the charger to carefully monitor battery parameters such as terminal voltage and temperature to prevent overcharging and damage to the cells. Such high charging rates are possible only with some battery types. Others will be damaged or possibly overheat or catch fire. Some may even explode.For example, an automobile SLI (starting, lighting, ignition) lead-acid battery carries several risks of explosion.